In reply to Removed Usermountbeckworth:
Over the years I've tried half a dozen or so colored chalks. Every one of them was less effective at its primary purpose, which is to keep hands dry and grease from being deposited on the holds.
I don't think there is anything to be done about the visual degradation, at least until authorities start banning climbing (which has started to happen...) By far the best approach (but only if widely adopted) is the chalk sock. The point is that climbers use way too much chalk; so much that they may even be decreasing their adherence. The chalk sock gives a much thinner dusting that barely transfers to the rock if at all. A problem is that more applications are needed.